title: Xylitol-mediated transient inhibition of ribitol utilization by Lactobacillus casei.
abstract: The growth of Lactobacillus casei strain Cl-16 at the expense or ribitol was inhibited if the non-metabolizable substrate xylitol was included in the medium at concentrations of 6 mM or greater. At these concentrations, xylitol, did not competitively inhibit ribitol transport. The cessation of growth was caused by the intracellular accumulation of xylitol-5-phosphate, which occurred because growth on ribitol had gratuitously induced a functional xylitol-specific phosphotransferase system but not the enzymes necessary for the further metabolism of xylitol-5-phosphate. Eventually, the cells overcame the xylitol-mediated inhibition by repressing the synthesis of enzyme II of the xylitol phosphotransferase system so that xylitol-5-phosphate would no longer be accumulated within the cell.
mesh_terms: D001426:Bacterial Proteins; D001692:Biological Transport / Q000187:drug effects; D004790:Enzyme Induction; D007780:Lacticaseibacillus casei / Q000254:growth & development / Q000378:metabolism*; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System / Q000096:biosynthesis / Q000378:metabolism; D012255:Ribitol / Q000378:metabolism*; D013401:Sugar Alcohol Dehydrogenases / Q000378:metabolism; D013402:Sugar Alcohols / Q000378:metabolism*; D014993:Xylitol / Q000378:metabolism / Q000494:pharmacology*
chemical_list: D001426:Bacterial Proteins; D013402:Sugar Alcohols; D012255:Ribitol; D013401:Sugar Alcohol Dehydrogenases; C034520:xylitol 5-phosphate dehydrogenase; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System; C034521:phosphoenolpyruvate-xylitol phosphotransferase, Lactobacillus casei; D014993:Xylitol